<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>

<body>

<div id="app">
    <h1>{{msg}}</h1>
</div>

<script src="../js/vue.js"></script>

<script>
    const app = Vue.createApp({
        data() {
            return {
                 msg: ""
             }
        }
    }).mount("#app");
</script>

</body>
</html>